JP2016051177A - Production method of optical film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical film having such characteristics that when a layer including an optical anisotropy layer in the optical film is transferred to a transfer target, the layer including the optical anisotropy layer can be uniformly released from a substrate and that decrease in an in-plane retardation value under high temperature drying conditions can be suppressed.SOLUTION: A production method of an optical film is provided, which includes: a step of applying a composition comprising a polymerizable liquid crystal compound on an alignment film of a laminate having a substrate and the alignment film; and a step of irradiating the laminate coated with the composition with active energy rays. The step of irradiating the laminate with active energy rays includes twice or more times of irradiation of active energy rays, in which a ratio of the energy of active energy rays in the first irradiation of active energy rays to the energy of active energy rays in the second irradiation of active energy rays satisfies a specific range, and the energy of active energy rays in the second irradiation of active energy rays is 10 to 10000 mJ/cm.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing an optical film having an optically anisotropic layer.

A flat panel display (FPD) includes members using optical films such as a polarizing plate and a retardation plate. Examples of such an optical film include an optical film having an optically anisotropic layer obtained by polymerizing a composition containing a polymerizable liquid crystal compound on a substrate.
It is known that the phase difference (Re (λ)) of an optical film given by light of wavelength λnm is determined by the product of the birefringence Δn and the thickness d of the film (Re (λ) = Δn × d ). The chromatic dispersion characteristic is usually represented by a value (Re (λ) / Re (550)) obtained by dividing the phase difference value Re (λ) at a certain wavelength λ by the phase difference value Re (550) at 550 nm. (Λ) / Re (550)) is in a wavelength range close to 1, or in a wavelength range showing reverse wavelength dispersion of Re (450) / Re (550) <1 and Re (650) / Re (550)> 1. It is known that uniform polarization conversion is possible.
In Patent Document 1, as a method for producing such an optical film having reverse wavelength dispersion, an optical material having the above reverse wavelength dispersion by polymerizing a polymerizable liquid crystal compound coated on a substrate by irradiation with ultraviolet light. A method for obtaining a film is disclosed.

Special table 2010-537955 gazette

  An optical film having an optically anisotropic layer manufactured by a conventional manufacturing method is used when a layer including an optically anisotropic layer formed on an alignment film of a substrate having an alignment film is transferred to a transfer target. Further, there has been a problem that the layer including the optically anisotropic layer cannot be uniformly peeled from the base material, and further, the in-plane retardation value is remarkably lowered under high temperature drying conditions.

The present invention includes the following inventions.
[1] A step of applying a composition containing a polymerizable liquid crystal compound on an alignment film of a laminate having a substrate and an alignment film, and a step of irradiating active energy rays to the laminate on which the composition is applied A method for producing an optical film comprising:
The step of irradiating the active energy ray includes two or more active energy ray irradiations, and includes an active energy ray energy in the first active energy ray irradiation and an active energy ray energy in the second active energy ray irradiation. The manufacturing method of the optical film whose ratio satisfy | fills following formula (2-1) and the energy of the active energy ray in the second active energy ray irradiation is 10-10000 mJ / cm < ² >.
15> (first irradiation energy) / (second irradiation energy)> 0.1 (2-1)
[2] In the step of irradiating the active energy ray, the intensity ratio between the wavelength of the active energy ray spectrum of 380 nm and the wavelength of 365 nm satisfies the following formula (1) in at least one active energy ray irradiation [1] The manufacturing method of the optical film of description.
Intensity of light having a wavelength of 380 nm / Intensity of light having a wavelength of 365 nm> 0.1 (1)
[3] The method for producing an optical film according to [1] or [2], wherein the active energy ray irradiation step includes active energy ray irradiation from a surface side on which the polymerizable liquid crystal compound is applied.
[4] Production of an optical film according to [3], wherein active energy rays are irradiated from the substrate side before, after or before and after irradiation of active energy rays from the surface side on which the polymerizable liquid crystal compound is applied. Method.
[5] The method for producing an optical film according to [3], wherein the active energy ray is irradiated from the polymerizable liquid crystal compound side after the active energy ray irradiation from the surface side on which the polymerizable liquid crystal compound is applied.
[6] The ratio of the energy of the active energy ray in the first active energy ray irradiation and the energy of the active energy ray in the second active energy ray irradiation satisfies the following formula (2-2) [1] to [ 5] The manufacturing method of the optical film in any one of.
10> (first irradiation energy) / (second irradiation energy)> 0.2 (2-2) [7] The optically anisotropic layer satisfies the following expressions (3) and (4). The method for producing an optical film according to any one of [1] to [6], wherein the optical film is a monolayer.
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
(In the formula, Re (λ) represents an in-plane retardation value for light having a wavelength of λ nm.)
[8] The method for producing an optical film according to any one of [1] to [7], wherein the optically anisotropic layer is an optically anisotropic layer satisfying the following formula (6-2).
100 nm <Re (550) <160 nm (6-2)
(In the formula, Re (550) represents an in-plane retardation value for light having a wavelength of 550 nm.)
[9] The method for producing an optical film according to any one of [1] to [8], wherein the thickness of the optically anisotropic layer is 0.3 to 5 μm.
[10] The method for producing an optical film according to any one of [1] to [9], wherein the composition containing the polymerizable liquid crystal compound is a composition containing a polymerizable liquid crystal compound and a polymerization initiator.
[11] The method for producing an optical film according to any one of [1] to [10], wherein the alignment film is a photo-alignment film.
[12] The method for producing an optical film according to any one of [1] to [10], wherein the alignment film has a thickness of 10 to 1000 nm.

  According to the present invention, transfer of a layer including an optically anisotropic layer formed on a substrate can be facilitated, and further, a decrease in in-plane retardation value under high temperature drying conditions can be suppressed.

An example of the active energy ray irradiation process in this invention is shown. An example of the active energy ray irradiation process in this invention is shown. An example of the active energy ray irradiation process in this invention is shown.

  In the present invention, a step of applying a composition containing a polymerizable liquid crystal compound (hereinafter sometimes referred to as a composition for forming an optically anisotropic layer) on an alignment film of a laminate having a substrate and an alignment film. including.

[Base material]
The substrate is preferably a resin substrate.
The resin substrate is usually a transparent resin substrate. The transparent resin base material means a base material having translucency capable of transmitting light, particularly visible light, and the translucency is a transmittance of 80% or more with respect to a light beam having a wavelength of 380 nm to 780 nm. The characteristic which becomes. As the resin substrate, a film is usually used, and a long film roll is preferably used.

  Polyethylene such as polyethylene, polypropylene and norbornene polymers; polyvinyl alcohol; polyethylene terephthalate; polymethacrylic acid ester; polyacrylic acid ester; cellulose ester; polyethylene naphthalate; polycarbonate; polysulfone; And sulfone; polyether ketone; polyphenylene sulfide; and polyphenylene oxide. Among them, a substrate made of polyolefin such as polyethylene, polypropylene, norbornene-based polymer is preferable.

  The substrate may be subjected to a surface treatment. Examples of the surface treatment method include a method of treating the surface of the substrate with corona or plasma in an atmosphere of vacuum to atmospheric pressure, a method of laser treating the substrate surface, a method of treating the substrate surface with ozone, A method of saponifying a material surface, a method of flame-treating a substrate surface, a method of applying a coupling agent to a substrate surface, a method of primer-treating a substrate surface, and a reactive monomer or a reactive polymer Examples of the method include a method of carrying out graft polymerization in which a reaction is performed by irradiating radiation, plasma, or ultraviolet light after being attached to the substrate surface. Among these, a method of corona or plasma treatment of the substrate surface in an atmosphere of vacuum to atmospheric pressure is preferable.

  As a method of performing surface treatment of the substrate with corona or plasma, a method of performing substrate surface treatment by generating a corona or plasma by installing a substrate between opposed electrodes under a pressure near atmospheric pressure, A gas is caused to flow between the electrodes facing each other, the gas is turned into plasma between the electrodes, and the plasma-treated gas is sprayed onto the base material. Under low pressure conditions, glow discharge plasma is generated to perform surface treatment of the base material. A method is mentioned.

  In particular, under a pressure close to atmospheric pressure, a substrate is placed between opposed electrodes and a corona or plasma is generated to treat the surface of the substrate, or a gas is flowed between the opposed electrodes between the electrodes. A method in which the gas is converted into plasma and the plasmaized gas is sprayed onto the substrate is preferable. Such surface treatment with corona or plasma is usually performed by a commercially available surface treatment apparatus.

  The base material may have a protective film on the surface opposite to the surface on which the composition for forming an optically anisotropic layer is applied. Examples of the protective film include films such as polyethylene, polyethylene terephthalate, polycarbonate, and polyolefin, and films having an adhesive layer on the film. Of these, polyethylene terephthalate is preferred because of its small thermal deformation during drying. By having the protective film on the surface opposite to the surface on which the composition for forming an optically anisotropic layer of the base material is applied, it is possible to suppress film shaking during substrate transport and slight vibration of the coated surface. The uniformity of the coating film can be improved.

  The thickness of the substrate is usually 5 μm to 300 μm, preferably 20 μm to 200 μm.

  The length of the long film roll in the longitudinal direction is usually 10 m to 4000 m, preferably 100 m to 3000 m. The length in the short direction of the long film roll is usually 0.1 m to 5 m, preferably 0.2 m to 2 m.

[Alignment film]
An alignment film is formed on the surface of the substrate on which the composition for forming an optically anisotropic layer is applied.
The alignment film has an alignment regulating force for aligning a polymerizable liquid crystal compound described later in a desired direction.
The alignment film has solvent resistance that does not dissolve when the composition for forming an optically anisotropic layer is applied, and has heat resistance in heat treatment for removal of the solvent and alignment of the polymerizable liquid crystal compound described below. Those are preferred. Examples of the alignment film include an alignment film containing an alignment polymer, a photo-alignment film, and a groove alignment film having a concavo-convex pattern and a plurality of grooves on the surface.

  Such an alignment film facilitates the alignment of the polymerizable liquid crystal compound. In addition, various orientations such as horizontal orientation, vertical orientation, hybrid orientation, and tilt orientation can be controlled depending on the type of the orientation film and rubbing conditions.

  The thickness of the alignment film is usually in the range of 10 nm to 10000 nm, preferably in the range of 10 nm to 2000 nm, and more preferably in the range of 10 nm to 1000 nm.

[Alignment film containing orientation polymer]
Examples of the orientation polymer include polyamides and gelatins having an amide bond, polyimides having an imide bond, and polyamic acid, polyvinyl alcohol, alkyl-modified polyvinyl alcohol, polyacrylamide, polyoxazole, polyethyleneimine, polystyrene, polyvinyl, which are hydrolyzed products thereof. Examples include pyrrolidone, polyacrylic acid and polyacrylic acid esters. Among these, polyvinyl alcohol is preferable. Two or more kinds of orientation polymers may be combined.

  An alignment film containing an alignment polymer is usually formed by applying an alignment polymer composition in which an alignment polymer is dissolved in a solvent to a substrate and removing the solvent to form a coating film, or based on the alignment polymer composition. It is obtained by applying to a material, removing the solvent to form a coating film, and rubbing the coating film.

  Examples of the solvent include water, methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether and other alcohol solvents, ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Propylene glycol methyl ether acetate, ester solvents such as ethyl lactate, ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, methyl isobutyl ketone, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, toluene, Aromatic hydrocarbon solvents such as xylene, nitrile solvents such as acetonitrile, ethers such as tetrahydrofuran and dimethoxyethane Agent, and, chloroform, chlorinated hydrocarbon solvents such as chlorobenzene. Two or more solvents may be combined.

  The concentration of the orienting polymer in the orienting polymer composition may be in a range where the orienting polymer is completely dissolved in the solvent. The content of the orientation polymer with respect to the orientation polymer composition is preferably 0.1 to 20% by mass, more preferably 0.1 to 10% by mass.

  Oriented polymer compositions are commercially available. Examples of the commercially available oriented polymer composition include Sanever (registered trademark, manufactured by Nissan Chemical Industries, Ltd.), Optmer (registered trademark, manufactured by JSR).

  Examples of methods for applying the alignment polymer composition to the substrate include spin coating, extrusion, gravure coating, die coating, slit coating, bar coating, applicator and other application methods, flexo methods, etc. There are known methods such as the printing method. When the optically anisotropic layer is produced by a roll to roll type continuous production method described later, a printing method such as a gravure coating method, a die coating method, or a flexo method is usually employed as the coating method.

  Examples of the method for removing the solvent contained in the oriented polymer composition include natural drying, ventilation drying, heat drying, vacuum drying, and a combination thereof. 10-250 degreeC is preferable and, as for drying temperature, 25-200 degreeC is more preferable. The drying time is preferably 5 seconds to 60 minutes, more preferably 10 seconds to 30 minutes, although it depends on the type of solvent.

  The coating film formed from the orientation polymer composition may be rubbed. By performing the rubbing treatment, an alignment regulating force can be imparted to the coating film.

Examples of the rubbing treatment include a method in which a rubbing cloth is wound and the coating film is brought into contact with a rotating rubbing roll.
If masking is performed when the rubbing treatment is performed, a plurality of regions (patterns) having different orientation directions can be formed in the alignment film.

[Photo-alignment film]
The photo-alignment film is usually obtained by applying a photo-alignment film-forming composition containing a polymer or monomer having a photoreactive group and a solvent to a substrate and irradiating with polarized light (preferably polarized UV). . The photo-alignment film can arbitrarily control the direction of the alignment regulating force by selecting the polarization direction of the polarized light to be irradiated.

  The photoreactive group refers to a group that generates alignment ability when irradiated with light. Specific examples include groups that are involved in photoreactions that are the origin of alignment ability, such as alignment-induced reactions, isomerization reactions, photodimerization reactions, photocrosslinking reactions, or photodecomposition reactions of molecules generated by light irradiation. As the photoreactive group, an unsaturated bond, particularly a group having a double bond is preferable, and a carbon-carbon double bond (C = C bond), a carbon-nitrogen double bond (C = N bond), and nitrogen-nitrogen. A group having at least one selected from the group consisting of a double bond (N═N bond) and a carbon-oxygen double bond (C═O bond) is particularly preferred.

  Examples of the photoreactive group having a C═C bond include a vinyl group, a polyene group, a stilbene group, a stilbazole group, a stilbazolium group, a chalcone group, and a cinnamoyl group. Examples of the photoreactive group having a C═N bond include groups having a structure such as an aromatic Schiff base and an aromatic hydrazone. Examples of the photoreactive group having an N = N bond include an azobenzene group, an azonaphthalene group, an aromatic heterocyclic azo group, a bisazo group, a formazan group, and a group having an azoxybenzene structure. Examples of the photoreactive group having a C═O bond include a benzophenone group, a coumarin group, an anthraquinone group, and a maleimide group. These groups may have a substituent such as an alkyl group, an alkoxy group, an aryl group, an allyloxy group, a cyano group, an alkoxycarbonyl group, a hydroxyl group, a sulfonic acid group, and a halogenated alkyl group.

  A group involved in the photodimerization reaction or the photocrosslinking reaction is preferable in terms of excellent orientation. Among them, a photoreactive group involved in the photodimerization reaction is preferable, and a cinnamoyl group is preferable in that a photoalignment film having a relatively small amount of polarized light irradiation necessary for alignment and having excellent thermal stability and stability over time can be easily obtained. And chalcone groups are preferred. As the polymer having a photoreactive group, a polymer having a cinnamoyl group in which the terminal portion of the polymer side chain has a cinnamic acid structure is particularly preferable.

  By applying the composition for forming a photo-alignment film on the substrate, the photo-alignment inducing layer can be formed on the substrate. Examples of the solvent contained in the composition include the same solvents as those contained in the orientation polymer composition described above, and can be selected according to the solubility of the polymer or monomer having a photoreactive group.

  The content of the polymer or monomer having a photoreactive group in the composition for forming a photoalignment film can be adjusted by the type of the polymer or monomer and the thickness of the target photoalignment film, and is at least 0.2% by mass or more. The range of 0.3 to 10% by mass is more preferable. As long as the characteristics of the photo-alignment film are not significantly impaired, the composition for forming a photo-alignment film may contain a polymer material such as polyvinyl alcohol or polyimide, or a photosensitizer.

  Examples of the method for applying the composition for forming a photo-alignment film to a substrate include the same methods as the method for applying the alignment polymer composition to a substrate. Examples of the method for removing the solvent from the applied composition for forming a photo-alignment film include the same method as the method for removing the solvent from the oriented polymer composition.

  In order to irradiate polarized light, even in the form of irradiating polarized light directly from the composition for forming a photo-alignment film applied on the substrate to which the solvent is removed, the polarized light is irradiated from the substrate side. It is also possible to irradiate through the material. The polarized light is preferably substantially parallel light. The wavelength of the polarized light to be irradiated is preferably in a wavelength region where the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) in the wavelength range of 250 nm to 400 nm is particularly preferable. Examples of the light source for irradiating the polarized light include xenon lamps, high-pressure mercury lamps, ultra-high pressure mercury lamps, metal halide lamps, ultraviolet lasers such as KrF and ArF, and the like. Among these, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, and a metal halide lamp are preferable because of high emission intensity of ultraviolet rays having a wavelength of 313 nm. By irradiating light from the light source through an appropriate polarizing layer, polarized UV can be irradiated. Examples of the polarizing layer include polarizing prisms such as polarizing filters, Glan Thompson, and Grand Taylor, and wire grid type polarizing layers.

  If masking is performed when polarized light irradiation is performed, a plurality of regions (patterns) having different orientation directions can be formed on the alignment film.

[Glub alignment film]
The groove alignment film is a film having a concavo-convex pattern or a plurality of grooves (grooves) on the film surface. When liquid crystal molecules are placed in a film having a plurality of linear grooves arranged at equal intervals, the liquid crystal molecules are aligned in the direction along the groove.

  As a method for obtaining a groove alignment film, a method of forming a concavo-convex pattern by performing development and rinsing after exposure through an exposure mask having a pattern-shaped slit on the photosensitive polyimide film surface, a plate having grooves on the surface A plurality of grooves are formed in the UV curable resin film formed on the base material, and a method of forming the UV curable resin layer before curing on the original master, transferring the resin layer to the base material, and then curing the resin layer. Examples include a method in which a roll-shaped master is pressed to form irregularities and then cured. Specific examples include the methods described in JP-A-6-34976 and JP-A-2011-242743.

  Among the methods described above, a method is preferable in which a roll-shaped master having a plurality of grooves is pressed against a film of a UV curable resin before curing formed on a substrate to form irregularities and then cured. As the roll master, stainless steel (SUS) is preferable from the viewpoint of durability.

Examples of the UV curable resin include monofunctional acrylates, polyfunctional acrylates, and mixtures thereof.
The monofunctional acrylate is a group selected from the group consisting of an acryloyloxy group (CH ₂ ═CH—COO—) and a methacryloyloxy group (CH ₂ ═C (CH ₃ ) —COO—) (hereinafter referred to as (meth) acryloyloxy). A compound that may be referred to as a group). In the present specification, “(meth) acrylate” represents at least one selected from the group consisting of acrylate and methacrylate. Notations such as “(meth) acryloyl” and “(meth) acrylic acid” have the same meaning.

  Monofunctional acrylates having one (meth) acryloyloxy group include alkyl (meth) acrylates having 4 to 16 carbon atoms, β-carboxyalkyl (meth) acrylates having 2 to 14 carbon atoms, and alkylation having 2 to 14 carbon atoms. Examples include phenyl (meth) acrylate, methoxypolyethylene glycol (meth) acrylate, phenoxypolyethylene glycol (meth) acrylate, and isobornyl (meth) acrylate.

  The polyfunctional acrylate is a compound having 2 or more (meth) acryloyloxy groups, and a compound having 2 to 6 (meth) acryloyloxy groups is preferable.

  As polyfunctional acrylates having two (meth) acryloyloxy groups, 1,3-butanediol di (meth) acrylate; 1,4-butanediol di (meth) acrylate; 1,6-hexanediol di (meth) Acrylate; ethylene glycol di (meth) acrylate; diethylene glycol di (meth) acrylate; neopentyl glycol di (meth) acrylate; triethylene glycol di (meth) acrylate; tetraethylene glycol di (meth) acrylate; polyethylene glycol diacrylate; A bis (acryloyloxyethyl) ether; ethoxylated bisphenol A di (meth) acrylate; propoxylated neopentyl glycol di (meth) acrylate; ethoxylated neopentylglyco Distearate (meth) acrylate and 3-methyl-pentanediol di (meth) acrylate.

As the polyfunctional acrylate having 3 to 6 (meth) acryloyloxy groups,
Trimethylolpropane tri (meth) acrylate; pentaerythritol tri (meth) acrylate; tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; ethoxylated trimethylolpropane tri (meth) acrylate; propoxylated trimethylolpropane tri ( Pentaerythritol tetra (meth) acrylate; dipentaerythritol penta (meth) acrylate; dipentaerythritol hexa (meth) acrylate; tripentaerythritol tetra (meth) acrylate; tripentaerythritol penta (meth) acrylate; tripenta Erythritol hexa (meth) acrylate; tripentaerythritol hepta (meth) acrylate; tripentaerythritol o Data (meth) acrylate;
Reaction product of pentaerythritol tri (meth) acrylate and acid anhydride; Reaction product of dipentaerythritol penta (meth) acrylate and acid anhydride;
A reaction product of tripentaerythritol hepta (meth) acrylate and an acid anhydride;
Caprolactone-modified trimethylolpropane tri (meth) acrylate; caprolactone-modified pentaerythritol tri (meth) acrylate; caprolactone-modified tris (2-hydroxyethyl) isocyanurate tri (meth) acrylate; caprolactone-modified pentaerythritol tetra (meth) acrylate; caprolactone-modified Dipentaerythritol penta (meth) acrylate; caprolactone-modified dipentaerythritol hexa (meth) acrylate; caprolactone-modified tripentaerythritol tetra (meth) acrylate; caprolactone-modified tripentaerythritol penta (meth) acrylate; caprolactone-modified tripentaerythritol hexa (meth) ) Acrylate; caprolactone-modified tripentaerys Tall hepta (meth) acrylate; caprolactone-modified tripentaerythritol octa (meth) acrylate; reaction product of caprolactone-modified pentaerythritol tri (meth) acrylate and acid anhydride; caprolactone-modified dipentaerythritol penta (meth) acrylate and acid anhydride And a reaction product of caprolactone-modified tripentaerythritol hepta (meth) acrylate and an acid anhydride.
The caprolactone modification means that a ring-opened product of caprolactone or a ring-opened polymer is introduced between the alcohol-derived site of the (meth) acrylate compound and the (meth) acryloyloxy group.

  Multifunctional acrylates are commercially available. Commercially available products include A-DOD-N, A-HD-N, A-NOD-N, APG-100, APG-200, APG-400, A-GLY-9E, A-GLY-20E, A-TMM. -3, A-TMPT, AD-TMP, ATM-35E, A-TMMT, A-9550, A-DPH, HD-N, NOD-N, NPG, TMPT [Shin Nakamura Chemical Co., Ltd.], "ARONIX M -220 "," M-325 "," M-240 "," M-270 "," M-309 "," M-310 "," M-321 "," M-350 " "M-360", "M-305", "M-306", "M-450", "M-451", "M-408", "M-400", "M-402", "M-403", "M-404", "M-405", "M-" 06 "[Toa Gosei Co., Ltd.]," EBECRYL11 "," 145 "," 150 "," 40 "," 140 "," 180 ", DPGDA, HDDA, TPGDA, HPNDA, PETIA, PETRA , TMPTA, TMPEOTA, DPHA, EBECRYL series [Daicel Cytec Co., Ltd.] and the like.

  In order to obtain an orientation with a small alignment disorder, the width of the convex portion of the groove alignment film is preferably 50 nm to 5000 nm, the width of the concave portion is preferably 100 nm to 5000 μm, and the depth of the uneven step is 2000 nm. Or less, preferably 10 nm to 200 nm or less.

  It is preferable to use a photo-alignment film that produces an alignment-controlling force by light irradiation in that an optically anisotropic layer can be repeatedly produced while maintaining the alignment-controlling power of the alignment film.

[Composition for forming optically anisotropic layer]
The composition for forming an optically anisotropic layer contains at least a polymerizable liquid crystal compound.

[Polymerizable liquid crystal compound]
Examples of the polymerizable liquid crystal compound include a compound containing a group represented by the formula (X) (hereinafter sometimes referred to as “compound (X)”). One type of polymerizable liquid crystal compound may be used, or a plurality of compounds having different structures may be combined.
^{P 11 -B 11 -E 11 -B 12} -A 11 -B 13 - (X)
[In formula (X), P ¹¹ represents a polymerizable group.
A ¹¹ represents a divalent alicyclic hydrocarbon group or a divalent aromatic hydrocarbon group. The hydrogen atom contained in the divalent alicyclic hydrocarbon group and divalent aromatic hydrocarbon group is a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group. The hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
B ¹¹ is —O—, —S—, —CO—O—, —O—CO—, —O—CO—O—, —CO—NR ¹⁶ —, —NR ¹⁶ —CO—, —CO—, -CS- or a single bond is represented. R ¹⁶ represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
B ¹² and ^{B 13} are each _{independently, -C≡C -, - CH = CH} -, - CH 2 -CH 2 -, - O -, - S -, - C (= O) -, - C ( = O) -O-, -OC (= O)-, -O-C (= O) -O-, -CH = N-, -N = CH-, -N = N-, -C ( ═O) —NR ¹⁶ —, —NR ¹⁶ —C (═O) —, —OCH ₂ —, —OCF ₂ —, —CH ₂ O—, —CF ₂ O—, —CH═CH—C (═O ) —O—, —O—C (═O) —CH═CH— or a single bond.
E ¹¹ represents an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and hydrogen contained in the alkoxy group The atom may be substituted with a halogen atom. In addition, —CH ₂ — constituting the alkanediyl group may be replaced by —O— or —CO—. ]

The number of carbon atoms of the divalent aromatic hydrocarbon group and divalent alicyclic hydrocarbon group represented by A ¹¹ is preferably in the range of 3 to 18, more preferably in the range of 5 to 12. It is preferably 5 or 6, and particularly preferably. A ¹¹ is preferably a cyclohexane-1,4-diyl group or a 1,4-phenylene group.

The alkanediyl group having 1 to 12 carbon atoms represented by E ^11, an alkanediyl group having 1 to 12 carbon atoms and is preferably linear. —CH ₂ — constituting the alkanediyl group having 1 to 12 carbon atoms may be replaced by —O—.
Specifically, methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane -1,7-diyl group, octane-1,8-diyl group, nonane-1,9-diyl group, decane-1,10-diyl group, undecane-1,11-diyl group and dodecane-1,12- A linear alkanediyl group having 1 to 12 carbon atoms such as a diyl group; —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —, —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—; CH ₂ —CH ₂ — and —CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—CH ₂ —CH ₂ —O—CH ₂ —CH ₂ — and the like can be mentioned.
B ¹¹ is preferably —O—, —S—, —CO—O—, or —O—CO—, and more preferably —CO—O—.
B ¹² and B ¹³ are each independently —O—, —S—, —C (═O) —, —C (═O) —O—, —O—C (═O) —, —O. —C (═O) —O— is preferable, and —O— or —O—C (═O) —O— is more preferable.

［式（Ｐ−１１）〜（Ｐ−１３）中、
Ｒ^１７〜Ｒ^２１はそれぞれ独立に、炭素数１〜６のアルキル基または水素原子を表わす。］ The polymerizable group represented by P ¹¹ is preferably a radically polymerizable group or a cationically polymerizable group in that it easily undergoes a photopolymerization reaction, and is easy to handle and easy to produce a polymerizable liquid crystal compound itself. Therefore, the polymerizable group is preferably a group represented by the following formula (P-11) to formula (P-15) or a stilbene group.

[In the formulas (P-11) to (P-13),
R ^{17 to} R ²¹ each independently represents an alkyl group having 1 to 6 carbon atoms or a hydrogen atom. ]

Specific examples of the group represented by the formula (P-11) to the formula (P-13) include a group represented by the following formula (P-16) to the formula (P-20) or a p-stilbene group.

P ¹¹ is preferably a group represented by Formula (P-14) to Formula (P-20), and more preferably a vinyl group, an epoxy group, or an oxetanyl group.
More preferably, the group represented by P ¹¹ -B ^11- is an acryloyloxy group or a methacryloyloxy group.

Examples of compound (X) include compounds represented by formula (I), formula (II), formula (III), formula (IV), formula (V) or formula (VI).
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -B ¹⁶ -E ¹² -B ¹⁷ -P ¹² (I)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -A ¹⁴ -F ¹¹ (II)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -B ¹⁵ -E ¹² -B ¹⁷ -P ¹² (III)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -A ¹³ -F ¹¹ (IV)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -B ¹⁴ -E ¹² -B ¹⁷ -P ¹² (V)
P ¹¹ -B ¹¹ -E ¹¹ -B ¹² -A ¹¹ -B ¹³ -A ¹² -F ¹¹ (VI)
(Where
A ^{12 to} A ¹⁴ are each independently synonymous with A ¹¹ , B ^{14 to} B ¹⁶ are each independently synonymous with B ¹² , B ¹⁷ is synonymous with B ¹¹ , and E ¹² is E ¹¹ is synonymous.
F ¹¹ is a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group. Represents a group (—SO ₃ H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms or a halogen atom, and —CH ₂ — constituting the alkyl group and the alkoxy group is replaced by —O—. Also good.
P ¹² has ^the same meaning as ^{P 11.} )

  Specific examples of the polymerizable liquid crystal compound include “3.8.6 Network (fully cross-linked type)” and “6” of Liquid Crystal Handbook (Edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd., October 30, 2000). .5.1 Liquid Crystal Material b. Polymerizable Nematic Liquid Crystal Material ”, JP 2010-31223 A, JP 2010-270108 A, JP 2011-6360 A, and JP 2011-207765 A. Among these compounds, compounds having a polymerizable group and having a maximum absorption wavelength at 250 nm to 370 nm can be mentioned.

  Specific examples of the compound (X) include the following formula (I-1) to formula (I-4), formula (II-1) to formula (II-4), formula (III-1) to formula (III- 22), compounds represented by formula (IV-1) to formula (IV-19), formula (V-1) to formula (V-2) and formula (VI-1) to formula (VI-6). It is done. In the following formulae, k1 and k2 each independently represents an integer of 2 to 12. These compounds (X) are preferable from the viewpoint of easy synthesis or availability.

［式（Ａ）中、
Ｘ^１は、酸素原子、硫黄原子またはＮＲ^１−を表わす。Ｒ^１は、水素原子または炭素数１〜４のアルキル基を表わす。
Ｙ^１は、置換基を有していてもよい炭素数６〜１２の１価の芳香族炭化水素基または置換基を有していてもよい炭素数３〜１２の１価の芳香族複素環式基を表わす。
Ｑ^３およびＱ^４は、それぞれ独立に、水素原子、置換基を有していてもよい炭素数１〜２０の１価の脂肪族炭化水素基、炭素数３〜２０の１価の脂環式炭化水素基、置換基を有していてもよい炭素数６〜２０の１価の芳香族炭化水素基、ハロゲン原子、シアノ基、ニトロ基、−ＮＲ^２Ｒ^３または−ＳＲ^２を表わすか、または、Ｑ^３とＱ^４とが互いに結合して、これらが結合する炭素原子とともに芳香環または芳香族複素環を形成する。Ｒ^２およびＲ^３は、それぞれ独立に、水素原子または炭素数１〜６のアルキル基を表わす。
Ｄ^１およびＤ^２は、それぞれ独立に、単結合、−Ｃ（＝Ｏ）−Ｏ−、−Ｃ（＝Ｓ）−Ｏ−、−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−ＣＲ^６Ｒ^７−、−Ｏ−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−Ｏ−ＣＲ^６Ｒ^７−、−ＣＯ−Ｏ−ＣＲ^４Ｒ^５−、−Ｏ−ＣＯ−ＣＲ^４Ｒ^５−、−ＣＲ^４Ｒ^５−Ｏ−ＣＯ−ＣＲ^６Ｒ^７−、−ＣＲ^４Ｒ^５−ＣＯ−Ｏ−ＣＲ^６Ｒ^７−またはＮＲ^４−ＣＲ^５Ｒ^６−またはＣＯ−ＮＲ^４−を表わす。
Ｒ^４、Ｒ^５、Ｒ^６およびＲ^７は、それぞれ独立に、水素原子、フッ素原子または炭素数１〜４のアルキル基を表わす。
Ｇ^１およびＧ^２は、それぞれ独立に、炭素数５〜８の２価の脂環式炭化水素基を表わし、該脂環式炭化水素基を構成するメチレン基は、酸素原子、硫黄原子またはＮＨ−に置き換っていてもよく、該脂環式炭化水素基を構成するメチン基は、第三級窒素原子に置き換っていてもよい。
Ｌ^１およびＬ^２は、それぞれ独立に、１価の有機基を表わし、Ｌ^１およびＬ^２のうちの少なくとも一つは、重合性基を有する。］
で表される化合物も挙げられ、Ｌ^１が式（Ａ１）で表される基であり、かつ、Ｌ^２が式（Ａ２）で表される基である式（Ａ）で表される化合物が好ましい。
Ｐ^１−Ｆ^１−（Ｂ^１−Ａ^１）_ｋ−Ｅ^１− （Ａ１）
Ｐ^２−Ｆ^２−（Ｂ^２−Ａ^２）_ｌ−Ｅ^２− （Ａ２）
［式（Ａ１）および式（Ａ２）中、
Ｂ^１、Ｂ^２、Ｅ^１およびＥ^２は、それぞれ独立に、−ＣＲ^４Ｒ^５−、−ＣＨ_２−ＣＨ_２−、−Ｏ−、−Ｓ−、−ＣＯ−Ｏ−、−Ｏ−ＣＯ−Ｏ−、−ＣＳ−Ｏ−、−Ｏ−ＣＳ−Ｏ−、−ＣＯ−ＮＲ¹−、−Ｏ−ＣＨ_２−、−Ｓ−ＣＨ_２−または単結合を表わす。
Ａ^１およびＡ^２は、それぞれ独立に、炭素数５〜８の２価の脂環式炭化水素基または炭素数６〜１８の２価の芳香族炭化水素基を表わし、該脂環式炭化水素基を構成するメチレン基は、酸素原子、硫黄原子またはＮＨ−に置き換っていてもよく、該脂環式炭化水素基を構成するメチン基は、第三級窒素原子に置き換っていてもよい。
ｋおよびｌは、それぞれ独立に、０〜３の整数を表わす。
Ｆ^１およびＦ^２は、炭素数１〜１２の２価の脂肪族炭化水素基を表わす。
Ｐ^１は、重合性基を表わす。
Ｐ^２は、水素原子または重合性基を表わす。
Ｒ^４およびＲ^５は、それぞれ独立に、水素原子、フッ素原子または炭素数１〜４のアルキル基を表わす。］ Examples of the polymerizable liquid crystal compound also include a compound represented by the formula (A) (hereinafter sometimes referred to as “compound (A)”).
Examples of the compound (A) include polymerizable liquid crystal compounds described in JP-T-2011-207765.

[In the formula (A),
X ¹ represents an oxygen atom, a sulfur atom or NR ^1- . R ¹ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
Y ¹ is an optionally substituted monovalent aromatic hydrocarbon group having 6 to 12 carbon atoms or an optionally substituted monovalent aromatic heterocyclic ring having 3 to 12 carbon atoms. Represents a formula group.
Q ³ and Q ⁴ are each independently a hydrogen atom, an optionally substituted monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent alicyclic group having 3 to 20 carbon atoms. A hydrocarbon group, a monovalent aromatic hydrocarbon group having 6 to 20 carbon atoms which may have a substituent, a halogen atom, a cyano group, a nitro group, —NR ² R ³ or —SR ² ; Alternatively, Q ³ and Q ⁴ are bonded to each other to form an aromatic ring or an aromatic heterocyclic ring together with the carbon atom to which they are bonded. R ² and R ³ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
D ¹ and D ² are each independently a single bond, —C (═O) —O—, —C (═S) —O—, —CR ⁴ R ⁵ —, —CR ⁴ R ⁵ —CR ⁶ R ^{7 -, - O-CR 4} R 5 -, - CR 4 R 5 -O-CR 6 R 7 -, - CO-O-CR 4 R 5 -, - O-CO-CR 4 R 5 -, - CR ^{4 R 5 -O-CO-CR} 6 R 7 -, - CR 4 R 5 -CO-O-CR 6 R 7 - or ^NR 4 ^-CR 5 ^{R 6} - or CO-NR ⁴ - represents a.
R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms.
G ¹ and G ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms, and the methylene group constituting the alicyclic hydrocarbon group is an oxygen atom, a sulfur atom or NH The methine group constituting the alicyclic hydrocarbon group may be replaced with a tertiary nitrogen atom.
L ¹ and L ² each independently represent a monovalent organic group, and at least one of L ¹ and L ² has a polymerizable group. ]
A compound represented by formula (A) in which L ¹ is a group represented by formula (A1) and L ² is a group represented by formula (A2). preferable.
P ¹ -F ^1- (B ¹ -A ¹ ) _k -E ^1- (A1)
P ² -F ^2- (B ² -A ² ) ₁ -E ^2- (A2)
[In Formula (A1) and Formula (A2),
^{B 1,} B 2, ^{E 1} and ^{E 2} are, each _{^{independently, -CR 4 R 5 -, -}} CH 2 -CH 2 -, - O -, - S -, - CO-O -, - O-CO It represents —O—, —CS—O—, —O—CS—O—, —CO—NR ¹ —, —O—CH ₂ —, —S—CH ₂ — or a single bond.
A ¹ and A ² each independently represent a divalent alicyclic hydrocarbon group having 5 to 8 carbon atoms or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and the alicyclic hydrocarbon The methylene group constituting the group may be replaced by an oxygen atom, a sulfur atom or NH-, and the methine group constituting the alicyclic hydrocarbon group is replaced by a tertiary nitrogen atom. Also good.
k and l each independently represents an integer of 0 to 3.
F ¹ and F ² represent a divalent aliphatic hydrocarbon group having 1 to 12 carbon atoms.
P ¹ represents a polymerizable group.
P ² represents a hydrogen atom or a polymerizable group.
R ⁴ and R ⁵ each independently represents a hydrogen atom, a fluorine atom or an alkyl group having 1 to 4 carbon atoms. ]

  The content of the polymerizable liquid crystal compound in the composition for forming an optically anisotropic layer is usually 5 to 50 parts by weight, preferably 10 to 30 parts by weight with respect to 100 parts by weight of the composition for forming an optically anisotropic layer. Part.

[Other ingredients]
The composition for forming an optically anisotropic layer may contain known components such as a photopolymerization initiator, a solvent, a polymerization inhibitor, a photosensitizer, a leveling agent, and a chiral agent in addition to the polymerizable liquid crystal compound.

[Photopolymerization initiator]
As the photopolymerization initiator, those that generate radicals upon irradiation with light are preferable.
Examples of the photopolymerization initiator include benzoin compounds, benzophenone compounds, benzyl ketal compounds, α-hydroxyketone compounds, α-aminoketone compounds, α-acetophenone compounds, triazine compounds, iodonium salts, and sulfonium salts. Specifically, Irgacure (registered trademark) 907, Irgacure 184, Irgacure 651, Irgacure 819, Irgacure 250, Irgacure 369 (all of which are manufactured by Ciba Japan Co., Ltd.), Sequol (registered trademark) BZ, Sequol Z , Sequol BEE (all manufactured by Seiko Chemical Co., Ltd.), kayacure (registered trademark) BP100 (manufactured by Nippon Kayaku Co., Ltd.), Kayacure UVI-6992 (produced by Dow), Adekaoptomer (registered trademark) SP -152, Adekaoptomer SP-170 (all manufactured by ADEKA Corporation), TAZ-A, TAZ-PP (all manufactured by Nippon Siebel Hegner) and TAZ-104 (manufactured by Sanwa Chemical Co., Ltd.). Of these, α-acetophenone compounds are preferable, and examples of α-acetophenone compounds include 2-methyl-2-morpholino-1- (4-methylsulfanylphenyl) propan-1-one, 2-dimethylamino-1- (4-morpholino Phenyl) -2-benzylbutan-1-one, 2-dimethylamino-1- (4-morpholinophenyl) -2- (4-methylphenylmethyl) butan-1-one and the like, more preferably 2- And methyl-2-morpholino-1- (4-methylsulfanylphenyl) propan-1-one and 2-dimethylamino-1- (4-morpholinophenyl) -2-benzylbutan-1-one. Examples of commercially available products of α-acetophenone compounds include Irgacure 369, 379EG, 907 (above, manufactured by BASF Japan Ltd.), Sequol BEE (manufactured by Seiko Chemical Co., Ltd.), and the like.

  Since a photoinitiator can fully utilize energy emitted from a light source and is excellent in productivity, the maximum absorption wavelength is preferably 300 nm to 380 nm, and more preferably 300 nm to 360 nm.

  The content of the polymerization initiator is usually 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound in order to polymerize the polymerizable liquid crystal compound without disturbing the orientation of the polymerizable liquid crystal compound. The amount is preferably 0.5 to 10 parts by mass.

[solvent]
As the solvent, an organic solvent capable of dissolving the constituent components of the optically anisotropic layer forming composition such as a polymerizable liquid crystal compound is preferable. A solvent that is soluble and is inert to the polymerization reaction of the polymerizable liquid crystal compound is more preferable.
Specifically, alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, methyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, phenol; ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, γ-butyrolactone, Ester solvents such as propylene glycol methyl ether acetate and ethyl lactate; Ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, methyl amyl ketone, and methyl isobutyl ketone; Non-chlorinated aliphatic hydrocarbon solvents such as pentane, hexane, and heptane Non-chlorinated aromatic hydrocarbon solvents such as toluene and xylene; nitrile solvents such as acetonitrile; tetrahydrofuran and dimethoxy Ethers Tan such solvents; include; and chloroform, chlorinated hydrocarbon solvents such as chlorobenzene. Two or more organic solvents may be used in combination. Among these, alcohol solvents, ester solvents, ketone solvents, non-chlorinated aliphatic hydrocarbon solvents and non-chlorinated aromatic hydrocarbon solvents are preferable.

  As for content of a solvent, 10-10000 mass parts is preferable with respect to 100 mass parts of solid content, More preferably, it is 100-5000 mass parts. The solid content concentration in the composition for forming an optically anisotropic layer is preferably 2 to 50% by mass, more preferably 5 to 50% by mass. The “solid content” means the total of components excluding the solvent from the composition for forming an optically anisotropic layer.

[Polymerization inhibitor]
The polymerization inhibitor can control the polymerization reaction of the polymerizable liquid crystal compound.
Polymerization inhibitors include hydroquinones having substituents such as hydroquinone and alkyl ethers; catechols having substituents such as alkyl ethers such as butylcatechol; pyrogallols, 2,2,6,6-tetramethyl-1- Radical scavengers such as piperidinyloxy radicals; thiophenols; β-naphthylamines and β-naphthols.
The content of the polymerization inhibitor is usually 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound in order to polymerize the polymerizable liquid crystal compound without disturbing the alignment of the polymerizable liquid crystal compound. Yes, preferably 0.5 to 10 parts by mass.

[Photosensitizer]
Examples of the photosensitizer include xanthones such as xanthone and thioxanthone; anthracene having a substituent such as anthracene and alkyl ether; phenothiazine; and rubrene.
By using a photosensitizer, the sensitivity of the photopolymerization initiator can be increased. Content of a photosensitizer is 0.1-30 mass parts normally with respect to 100 mass parts of polymeric liquid crystal compounds, Preferably it is 0.5-10 mass parts.

[Leveling agent]
Examples of the leveling agent include organic modified silicone oil-based, polyacrylate-based and perfluoroalkyl-based leveling agents. Specifically, DC3PA, SH7PA, DC11PA, SH28PA, SH29PA, SH30PA, ST80PA, ST86PA, SH8400, SH8700, FZ2123 (all are manufactured by Toray Dow Corning Co., Ltd.), KP321, KP323, KP324, KP326, KP340, KP341, X22-161A, KF6001 (all manufactured by Shin-Etsu Chemical Co., Ltd.), TSF400, TSF401, TSF410, TSF4300, TSF4440, TSF4445, TSF-4446, TSF4452, TSF4460 (all, Momentive Performance Materials Japan GK) ), Fluorinert (registered trademark) FC-72, FC-40, FC-43, FC-3283 (all of which are Sumitomo Three) Manufactured by M. Co., Ltd.), MegaFace (registered trademark) R-08, R-30, R-90, F-410, F-411, F-443, F-445, F- 470, F-477, F-479, F-482, F-482 (all of which are manufactured by DIC Corporation), Ftop (trade name) EF301, EF303, EF351, EF352 ( As described above, all manufactured by Mitsubishi Materials Electronics Chemical Co., Ltd.), Surflon (registered trademark) S-381, S-382, S-383, S-393, SC-101, SC-105, KH-40 SA-100 (all manufactured by AGC Seimi Chemical Co., Ltd.), trade name E1830, E5844 (manufactured by Daikin Fine Chemical Laboratory Co., Ltd.), BM-1000, BM-1100, BYK-352, BYK-353 and YK-361N (both trade name: BM Chemie Co., Ltd.) and the like. Two or more leveling agents may be combined.

By using a leveling agent, a smoother optically anisotropic layer can be formed.
Further, in the process of producing an optical film having an optically anisotropic layer, the fluidity of the composition for forming an optically anisotropic layer can be controlled, and the crosslinking density of the optically anisotropic film can be adjusted. Content of a leveling agent is 0.1-30 mass parts normally with respect to 100 mass parts of polymeric liquid crystal compounds, Preferably it is 0.1-10 mass parts.

[Chiral agent]
Examples of the chiral agent include known chiral agents (for example, liquid crystal device handbook, Chapter 3-4-3, TN, chiral agent for STN, 199 pages, edited by Japan Society for the Promotion of Science, 142nd Committee, 1989). It is done.
The chiral agent generally contains an asymmetric carbon atom, but an axially asymmetric compound or a planar asymmetric compound containing no asymmetric carbon atom can also be used as the chiral agent. Examples of the axial asymmetric compound or the planar asymmetric compound include binaphthyl, helicene, paracyclophane, and derivatives thereof.
Specifically, JP 2007-269640 A, JP 2007-269639 A, JP 2007-176870 A, JP 2003-13787 A, JP 2000-51596 A, JP 2007-169178 A. No. 9 and Japanese National Patent Publication No. 9-506088, and palocolor (registered trademark) LC756 manufactured by BASF Japan Ltd. is preferable.
The content of the chiral agent is usually 0.1 to 30 parts by mass with respect to 100 parts by mass of the polymerizable liquid crystal compound in order to polymerize the polymerizable liquid crystal compound without disturbing the alignment of the polymerizable liquid crystal compound. The amount is preferably 1.0 to 25 parts by mass.

[Formation of optically anisotropic layer]
As a method for applying the composition for forming an optically anisotropic layer on an alignment film of a substrate having an alignment film, an extrusion coating method, a direct gravure coating method, a reverse gravure coating method, a CAP coating method, a slit coating method, Examples include a die coating method. Moreover, the method of apply | coating using coaters, such as a dip coater, a bar coater, a spin coater, etc. are mentioned. Among these, a CAP coating method, an inkjet method, a dip coating method, a slit coating method, a die coating method, and a coating method using a bar coater are preferable because they can be continuously applied in the Roll to Roll format. When applying in roll to roll format, an alignment film forming composition or the like is applied to a substrate to form an alignment film, and the optically anisotropic layer forming composition is continuously formed on the obtained alignment film. It can also be applied.

  The present invention includes a step of irradiating active energy rays and a step of curing the polymerizable liquid crystal compound by the irradiation to form an optically anisotropic layer. The step of irradiating the active energy ray includes irradiation of the active energy ray twice or more. In the step of irradiating the active energy rays, the active energy rays are preferably irradiated twice or three times, and more preferably, the active energy rays are irradiated twice. By performing active energy ray irradiation for the second and subsequent times after irradiation of the first active energy ray, transfer of the layer including the formed optically anisotropic layer is facilitated, and further, in-plane under high temperature drying conditions There is a tendency that a decrease in the phase difference value can be suppressed.

In any active energy ray irradiation, the irradiation direction may be from the substrate side (hereinafter sometimes referred to as the A direction), or the surface on which the composition for forming an optically anisotropic layer is applied. Although it may be from the side (hereinafter sometimes referred to as the B direction), it is preferable that the active energy ray irradiation from the B direction is performed at least once.
In this specification, active energy ray irradiation from the A direction is opposite to the surface of the substrate, that is, the surface on which the alignment film coated with the composition for forming an optically anisotropic layer is formed. The irradiation of active energy rays in the direction from the surface side to the alignment film coated with the composition for forming an optically anisotropic layer is shown. Moreover, the active energy ray irradiation from the B direction means that the active energy ray is irradiated from the polymerizable liquid crystal compound side, that is, from the alignment film side coated with the composition for forming an optically anisotropic layer toward the substrate. Represents. The irradiation angle of the active energy ray may be perpendicular to the substrate surface or may be inclined with respect to the substrate surface.
After the active energy ray irradiation from the B direction, the active energy ray irradiation from the B direction is further performed, or the active energy ray from the A direction is performed before, after, or both before and after the active energy ray irradiation from the B direction. Irradiation is preferably performed. It is more preferable to perform active energy ray irradiation from the A direction after active energy ray irradiation from the B direction.

  When active energy ray irradiation is performed once each from the A direction and the B direction, there is a time interval between the end of the first active energy ray irradiation and the start of the second active energy ray irradiation. It does not have to be provided. At the same time as the irradiation of the first active energy ray is completed, the second active energy ray irradiation may be started, or the second active energy ray irradiation may be started during the first active energy ray irradiation. Good. Moreover, you may start active energy ray irradiation from the A direction and the B direction simultaneously. In this case, ultraviolet irradiation from the B direction is regarded as the first irradiation, and irradiation from the A direction is regarded as the second irradiation.

  When active energy ray irradiation is performed twice from the same direction, that is, when active energy ray irradiation is performed from the A direction and then active energy ray irradiation is performed again from the A direction, or active energy ray irradiation is performed from the B direction. Later, even if active energy ray irradiation is performed again from the B direction, if the first active energy ray can be substantially distinguished from the second active energy ray, the first active energy ray is used. There may be no time interval between the end of irradiation and the start of the second active energy ray irradiation. “Substantially distinguishable” means that the spectrum of active energy rays is different, the intensity of active energy rays is different, or the irradiation angle of active energy rays is different. If the first active energy ray and the second active energy ray are not substantially distinguishable, the first active energy ray irradiation ends and the second active energy ray irradiation starts. A time interval may be provided between the two so that they can be distinguished. Regardless of whether or not the first active energy ray and the second active energy ray can be substantially distinguished, the time interval between the first active energy ray irradiation and the second active energy ray irradiation is as follows. Any time interval can be selected, but it is preferably within one month, more preferably within one week, and even more preferably within one day.

  A film having optical anisotropy is obtained by irradiating the composition for forming an optical anisotropic film coated on the alignment film of the substrate having the alignment film with active energy rays to polymerize the polymerizable liquid crystal compound. It is done. Here, when the polymerizable liquid crystal compound contained in the composition for forming an optically anisotropic film applied on the alignment film exhibits a liquid crystal phase such as a nematic phase, the obtained optically anisotropic film has birefringence due to monodomain alignment. Have sex.

  The active energy ray irradiation may be performed on the applied optically anisotropic film-forming composition as it is, but when the optically anisotropic layer-forming composition contains a solvent, it is dried after coating and the solvent is removed. Irradiation with active energy rays is preferred. In this specification, what was dried after apply | coating the composition for optically anisotropic layer formation may be called a dry film. Although drying (removal of the solvent) may be performed in parallel with the irradiation with active energy rays, it is preferable to remove most of the solvent before the irradiation with active energy rays.

  Examples of the drying method include natural drying, ventilation drying, heat drying, vacuum drying, and a combination thereof. Of these, natural drying or heat drying is preferred. The drying temperature is preferably in the range of 0 to 250 ° C, more preferably in the range of 50 to 220 ° C, and still more preferably in the range of 60 to 170 ° C. The drying time is preferably 10 seconds to 20 minutes, more preferably 30 seconds to 10 minutes.

The liquid crystal alignment of the polymerizable liquid crystal is controlled by the properties of the alignment film and the polymerizable liquid crystal compound. For example, if the alignment film is a material that expresses a horizontal alignment regulating force as an alignment regulating force, the polymerizable liquid crystal compound can form a horizontal alignment or a hybrid alignment, and if it is a material that expresses a vertical alignment regulating force, The polymerizable liquid crystal compound can form a vertical alignment or a tilted alignment.
The alignment regulating force can be arbitrarily adjusted depending on the surface state and rubbing conditions when the alignment film is formed of an alignment polymer, and polarized irradiation conditions when it is formed of a photo-alignment polymer. It is possible to adjust arbitrarily by such as. The liquid crystal alignment can also be controlled by selecting physical properties such as surface tension and liquid crystallinity of the polymerizable liquid crystal compound.

[Active energy rays]
Photopolymerization is carried out by irradiating an active energy ray to a laminate on which a composition containing a polymerizable liquid crystal compound is applied. The active energy rays to be irradiated include the type of polymerizable liquid crystal compound contained in the dry film (particularly the type of photopolymerizable group possessed by the polymerizable liquid crystal compound), and the type of photopolymerization initiator when it contains a photopolymerization initiator. And the amount thereof are appropriately selected. Specifically, one or more kinds of light selected from the group consisting of visible light, ultraviolet light, infrared light, X-rays, α-rays, β-rays, and γ-rays can be used. Among them, ultraviolet light is preferable in that it is easy to control the progress of the polymerization reaction and that a photopolymerization apparatus widely used in this field can be used. It is preferable to select the kind of the liquid crystalline compound.

When the composition for forming an optically anisotropic layer contains a photopolymerization initiator, it is preferable to select the type of photopolymerization initiator so that it can be photopolymerized by ultraviolet light.
In the production method of the present invention, the intensity ratio between the wavelength 380 nm and the wavelength 365 nm of the active energy ray spectrum in at least one active energy ray irradiation preferably satisfies the following formula (1). More preferably, the ratio of the intensity of the active energy ray spectrum between the wavelength of 380 nm and the wavelength of 365 nm in any active energy ray irradiation satisfies the following formula (1).
Intensity of light of wavelength 380 nm / Intensity of light of wavelength 365 nm> 0.1 (1)

  It is preferable to irradiate the active energy ray satisfying the formula (1) at least once because the polymerizable liquid crystal compound can be efficiently polymerized. When the composition for forming an optically anisotropic layer contains a photopolymerization initiator, it is more preferable because the polymerizable liquid crystal compound can be polymerized more efficiently because the photopolymerization initiator has a high strength at the absorption wavelength.

  The ratio of the intensity between the wavelength of active energy ray spectrum of 380 nm and the wavelength of 365 nm preferably satisfies the formula (1). However, if the composition for forming an optically anisotropic layer can be cured, the energy of the active energy ray to be described later is appropriately selected. You can make adjustments.

  Further, the polymerization temperature can be controlled by irradiating with light while cooling the dry film by an appropriate cooling means during the polymerization. Since the alignment fluctuation of the liquid crystal occurs due to heating accompanying irradiation with active energy rays, the temperature of the polymerizable liquid crystal compound at the time of irradiation with active energy rays is preferably 30 ° C. or lower. By carrying out the polymerization of the polymerizable liquid crystal compound at a lower temperature by such cooling, an optically anisotropic layer can be appropriately formed even if a substrate having a relatively low heat resistance is used.

The manufacturing method of the optical film of this invention includes the active energy ray irradiation process which performs active energy ray irradiation at least twice. The energy of the active energy ray in the second and subsequent active energy ray irradiations is 10 to 10,000 mJ / cm ² . The energy of this active energy ray is preferably 10 to 3000 mJ / cm ² , more preferably 50 to 3000 mJ / cm ² , still more preferably 50 to 1000 mJ / cm ² , and even more preferably 100 to 700 mJ / cm ^2. cm ² , even more preferably 100 to 500 mJ / cm ² .
Moreover, it is preferable that ratio of the energy of the active energy ray in the first active energy ray irradiation and the energy of the active energy ray in the second active energy ray irradiation satisfies the following formula (2-1). It is more preferable to satisfy 2-2).
15> (first irradiation energy) / (second irradiation energy)> 0.1 (2-1) 10> (first irradiation energy) / (second irradiation energy)> 0.2 (2- 2) When the active energy ray satisfying the formula (2-1) or the formula (2-2) is irradiated, the transfer of the layer including the formed optically anisotropic layer becomes easier, and further, the in-plane retardation value is obtained. It is preferable because it is easier to suppress the decrease in the thickness.
Here, the energy of the active energy ray is synonymous with the integrated light amount of the active energy ray.

  As a light source of the active energy ray, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a halogen lamp, a carbon arc lamp, a tungsten lamp, a gallium lamp, an excimer laser, and a wavelength range of 380 to 440 nm are emitted. Examples include LED light sources, chemical lamps, black light lamps, microwave-excited mercury lamps, and metal halide lamps.

The time for irradiating light is usually 0.1 seconds to 10 minutes, preferably 0.1 seconds to 1 minute, more preferably 0.1 seconds to 30 seconds, and further preferably 0.1 seconds. -10 seconds.
If it is the said range, the optically anisotropic layer excellent in transparency can be obtained.

  The thickness of the optically anisotropic layer can be appropriately adjusted depending on the application, but is preferably 0.1 μm to 10 μm, more preferably 0.3 μm to 5 μm in view of reducing photoelasticity, and More preferably, it is 5 micrometers-3 micrometers.

As an optical film manufacturing method of the present invention, an example of a process for continuously manufacturing an optical anisotropic layer in the Roll to Roll format will be described with reference to FIGS.
In addition, in FIGS. 1-3, the ultraviolet-ray is used as an active energy ray. Further, the steps relating to the formation of the alignment film and the application and drying of the composition for forming an optically anisotropic layer are not shown in the figure. Furthermore, the cooling device at the time of ultraviolet irradiation does not need to exist. When the cooling device exists, the cooling device may be installed anywhere as long as the film can be cooled. Hereinafter, the case where the composition for forming an optically anisotropic layer is applied to the outer surface of a base roll to be unwound first will be described. It may be on either side of the winding inner surface or outer winding surface.

  FIG. 1A shows a step of continuously unwinding a substrate from a roll 1 wound around a core 1A, and an optically anisotropic layer-forming composition applied on an alignment film with ultraviolet irradiation. The apparatus 4 irradiates ultraviolet rays from the B direction and cools the optically anisotropic layer by the cooling device 3 installed at a position facing the ultraviolet irradiation apparatus 4 with the film interposed therebetween, and the polymerizable liquid crystal compound is polymerized. The base material having the optically anisotropic layer formed in this manner is wound on the core 2A to obtain the roll 2, and the roll 2 wound on the core 2A is transferred to the core 1A ′ and the roll 1 Ultraviolet ray from the B direction by the step of “obtaining”, the step of continuously unwinding the substrate having the optically anisotropic layer from the roll 1 ′ wound around the core 1A ′, and the ultraviolet irradiation device 4 ′. UV irradiation device 4 with film It includes an opposing cooling device 3 installed at a position and obtaining a take-up roll 2 'and cooling the liquid crystal, the substrate core 2A having the optically anisotropic layer' to.

  FIG. 1B shows the step of continuously unwinding the base material from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film with ultraviolet irradiation. The apparatus 4 irradiates ultraviolet rays from the direction A and cools the optically anisotropic layer by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the polymerizable liquid crystal compound is polymerized. The base material having the optically anisotropic layer formed in this manner is wound on the core 2A to obtain the roll 2, and the roll 2 wound on the core 2A is transferred to the core 1A ′ and the roll 1 Ultraviolet rays from the A direction by the step of “obtaining”, the step of continuously unwinding the substrate having the optically anisotropic layer from the roll 1 ′ wound around the core 1A ′, and the ultraviolet irradiation device 4 ′. UV irradiation device 4 with film It includes an opposing cooling device 3 installed at a position and obtaining a take-up roll 2 'and cooling the liquid crystal, the substrate core 2A having the optically anisotropic layer' to.

  FIG. 1 (c) shows the step of continuously unwinding the substrate from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film with ultraviolet irradiation. The apparatus 4 irradiates ultraviolet rays from the direction A and cools the optically anisotropic layer by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the polymerizable liquid crystal compound is polymerized. The base material having the optically anisotropic layer formed in this manner is wound on the core 2A to obtain the roll 2, and the roll 2 wound on the core 2A is transferred to the core 1A ′ and the roll 1 Ultraviolet ray from the B direction by the step of “obtaining”, the step of continuously unwinding the substrate having the optically anisotropic layer from the roll 1 ′ wound around the core 1A ′, and the ultraviolet irradiation device 4 ′. UV irradiation device 4 with film It includes an opposing cooling device 3 installed at a position and obtaining a take-up roll 2 'and cooling the liquid crystal, the substrate core 2A having the optically anisotropic layer' to.

  FIG. 1 (d) shows the step of continuously unwinding the substrate from the roll 1 wound around the core 1 </ b> A, and the composition for forming an optically anisotropic layer applied on the alignment film is irradiated with ultraviolet rays. The apparatus 4 irradiates ultraviolet rays from the B direction and cools the optically anisotropic layer by the cooling device 3 installed at a position facing the ultraviolet irradiation apparatus 4 with the film interposed therebetween, and the polymerizable liquid crystal compound is polymerized. The base material having the optically anisotropic layer formed in this manner is wound on the core 2A to obtain the roll 2, and the roll 2 wound on the core 2A is transferred to the core 1A ′ and the roll 1 Ultraviolet rays from the A direction by the step of “obtaining”, the step of continuously unwinding the substrate having the optically anisotropic layer from the roll 1 ′ wound around the core 1A ′, and the ultraviolet irradiation device 4 ′. UV irradiation device 4 with film Including an opposing cooling device 3 installed at a position and obtaining a take-up roll 2 'and cooling the liquid crystal, the substrate core 2A having the optically anisotropic layer' to.

  In FIGS. 1 (a) to (d), the base material having an optically anisotropic layer was wound around a roll every time ultraviolet irradiation was performed, but as shown in FIGS. 2 (a) to (d), You may perform at least 2 times of ultraviolet irradiation continuously.

  FIG. 2 (a) shows the step of continuously unwinding the substrate from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film is irradiated with ultraviolet rays. The apparatus 4 irradiates ultraviolet rays from the B direction, cools the liquid crystal by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the ultraviolet irradiation device 4 ′ from the B direction. A step of cooling the optically anisotropic layer with a cooling device 3 ′ disposed at a position facing the ultraviolet irradiating device 4 ′ while irradiating with an ultraviolet ray, and a substrate having the optically anisotropic layer; And a step of obtaining the winding roll 2 on the winding core 2A.

  FIG. 2 (b) shows the step of continuously unwinding the substrate from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film with ultraviolet irradiation. The apparatus 4 irradiates ultraviolet rays from the A direction, cools the liquid crystal by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the ultraviolet irradiation device 4 ′ from the B direction. A step of cooling the optically anisotropic layer with a cooling device 3 ′ disposed at a position facing the ultraviolet irradiating device 4 ′ while irradiating with an ultraviolet ray, and a substrate having the optically anisotropic layer; And a step of obtaining the winding roll 2 on the winding core 2A.

  FIG. 2 (c) shows the step of continuously unwinding the base material from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film is irradiated with ultraviolet rays. The apparatus 4 irradiates ultraviolet rays from the B direction, cools the liquid crystal by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the ultraviolet irradiation device 4 ′ from the A direction. A step of cooling the optically anisotropic layer with a cooling device 3 ′ disposed at a position facing the ultraviolet irradiating device 4 ′ while irradiating with an ultraviolet ray, and a substrate having the optically anisotropic layer; And a step of obtaining the winding roll 2 on the winding core 2A.

  FIG. 2 (d) shows the step of continuously unwinding the substrate from the roll 1 wound around the core 1A, and the composition for forming an optically anisotropic layer applied on the alignment film with ultraviolet irradiation. The apparatus 4 irradiates ultraviolet rays from the A direction and cools the liquid crystal by the cooling device 3 installed at a position facing the ultraviolet irradiation device 4 with the film interposed therebetween, and the ultraviolet irradiation device 4 ′ from the A direction. A step of cooling the optically anisotropic layer with a cooling device 3 ′ disposed at a position facing the ultraviolet irradiating device 4 ′ while irradiating with an ultraviolet ray, and a substrate having the optically anisotropic layer; And a step of obtaining the winding roll 2 on the winding core 2A.

  When the ultraviolet irradiation process is continuously performed as shown in FIGS. 2A to 2D, the number of times of film winding can be reduced, so that the productivity of the optical film can be improved.

  Moreover, as shown in FIG. 3, you may substantially irradiate ultraviolet rays twice by irradiating ultraviolet rays simultaneously from the A direction and the B direction, that is, from above and below with the film interposed therebetween. FIG. 3 shows a process of continuously unwinding a base material from a roll 1 wound around a core 1A, and an optically anisotropic layer forming composition applied on an alignment film by an ultraviolet irradiation device 4. A process of irradiating ultraviolet rays from the B direction, and a step of irradiating the ultraviolet rays from the A direction by the ultraviolet irradiation device 4 ′ disposed at a position facing the ultraviolet irradiation device 4 across the film, and the polymerizable liquid crystal compound is polymerized. A step of winding the base material having the optically anisotropic layer formed on the core 2A to obtain the roll 2.

[Optically anisotropic layer]
By the above-mentioned active energy ray irradiation, the polymerizable liquid crystal compound is cured and an optically anisotropic layer is formed. The optically anisotropic layer in the optical film produced by the production method of the present application preferably satisfies the following formulas (3) and (4).
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
Here, Re (450), Re (550), and Re (650) represent phase difference values for light having wavelengths of 450 nm, 550 nm, and 650 nm, respectively.

  In order to satisfy the formula (3) and the formula (4), the compound (A) may be contained as a polymerizable liquid crystal compound. Specifically, the method described in JP-T-2011-207765 can be mentioned.

By adjusting the amounts of the compound (X) and the compound (A) contained in the polymerizable liquid crystal forming the optically anisotropic layer, the retardation of the optically anisotropic layer can be prepared. In addition, since the retardation value (retardation value, Re (λ)) of the obtained optically anisotropic layer is determined as shown in Equation (5), Δn is used to obtain a desired Re (λ). (Λ) and the film thickness d may be adjusted as appropriate.
Re (λ) = d × Δn (λ) (5)
(In the formula, Re (λ) represents a retardation value at a wavelength λnm, d represents a film thickness, and Δn (λ) represents a birefringence at a wavelength λnm.)

The in-plane retardation value of the optically anisotropic layer with respect to light having a wavelength of 550 nm preferably satisfies the following formula (6), more preferably satisfies formula (6-1), and formula (6-2) It is more preferable to satisfy.
90 nm <Re (550) <180 nm (6)
95 nm <Re (550) <170 nm (6-1)
100 nm <Re (550) <160 nm (6-2)
Here, Re (550) represents an in-plane retardation value for light having a wavelength of 550 nm.

  The optically anisotropic layer in the optical film produced by the production method of the present invention converts linearly polarized light into circularly or elliptically polarized light, converts circularly or elliptically polarized light into linearly polarized light, or linearly polarized light. It is useful as a retardation film used for changing the direction. Moreover, a viewing angle compensation film, a viewing angle widening film, an antireflection film can be obtained by laminating a plurality of layers including an optically anisotropic layer in an optical film produced by the production method of the present application, or combining with other films. , A polarizing film, a circular polarizing film, an elliptical polarizing film, a brightness enhancement film, and the like.

  The optical film produced by the production method of the present invention has an optical anisotropy by peeling the substrate of the optical film after the optical film and the transfer object are bonded via an adhesive. It is easy to transfer the layer including the layer to the transfer target.

[Adhesive]
Examples of the adhesive used when the optical film manufactured by the manufacturing method of the present invention and the transfer target are bonded include a pressure-sensitive adhesive, an aqueous adhesive, and an active energy ray-curable adhesive. An adhesive layer is obtained by removing water from the aqueous adhesive applied to the optically anisotropic layer. Moreover, an adhesive layer is obtained by irradiating the active energy ray-curable adhesive applied to the optically anisotropic layer with active energy rays.

  In general, the pressure-sensitive adhesive is obtained by radical polymerization of an acrylic monomer mixture containing (meth) acrylic acid ester as a main component and a small amount of a (meth) acrylic monomer having a functional group in the presence of a polymerization initiator. An acrylic pressure-sensitive adhesive containing an acrylic resin having a glass transition temperature Tg of 0 ° C. or less and a crosslinking agent is preferably used.

Among (meth) acrylic acid esters, alkyl acrylates are preferable, and n-butyl acrylate, 2-methoxyethyl acrylate and ethoxymethyl acrylate are more preferable.

  As a method for forming the pressure-sensitive adhesive layer on the optical film produced by the production method of the present invention, for example, a release film is used as a base material, and the above-mentioned pressure-sensitive adhesive composition is applied onto the release film to produce a pressure-sensitive adhesive. A method of forming a layer and transferring the pressure-sensitive adhesive layer obtained on the surface of the layer including the optically anisotropic layer, and directly applying the above pressure-sensitive adhesive composition to the surface of the layer including the optically anisotropic layer Examples include a method of forming a layer.

  The release film is made of, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarylate, polypropylene, or polyethylene, and a silicone treatment is performed on the bonding surface with the adhesive layer of the substrate. Such a mold release treatment as described above can be performed. Such a release film is also called a separate film or a separator.

  The thickness of the pressure-sensitive adhesive layer is preferably 5 to 50 μm, and more preferably 5 to 30 μm. By setting the thickness of the pressure-sensitive adhesive layer to 30 μm or less, the adhesiveness under high temperature and high humidity is improved, and the possibility of occurrence of floating or peeling between the optically anisotropic layer and the pressure-sensitive adhesive layer is reduced. Tend.

  As a water-based adhesive, for example, a polyvinyl alcohol resin or a urethane resin is used as a main component, and a composition containing a crosslinking agent or a curable compound such as an isocyanate compound or an epoxy compound in order to improve adhesiveness. Is generally. The thickness of the adhesive layer after drying is usually about 0.001 to 5 μm, preferably 0.01 μm or more, preferably 2 μm or less, more preferably 1 μm or less.

  When polyvinyl alcohol resin is used as the main component of the water-based adhesive, in addition to partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, methylol group-modified polyvinyl alcohol, and amino A modified polyvinyl alcohol-based resin such as group-modified polyvinyl alcohol may be used. Such an aqueous solution of polyvinyl alcohol resin is used as an aqueous adhesive, and the concentration of the polyvinyl alcohol resin in the aqueous adhesive is usually 1 to 10 parts by weight with respect to 100 parts by weight of water, preferably 1 to 5 parts by weight.

  As described above, the water-based adhesive comprising an aqueous solution of a polyvinyl alcohol-based resin is cured such as a polyhydric aldehyde, a water-soluble epoxy resin, a melamine-based compound, a zirconia-based compound, and a zinc compound in order to improve adhesiveness. An active compound can be blended. Examples of water-soluble epoxy resins include water-soluble products obtained by reacting epichlorohydrin with polyamide polyamines obtained by reacting polyalkylene polyamines such as diethylenetriamine and triethylenetetramine with dicarboxylic acids such as adipic acid. There is a characteristic polyamide epoxy resin. As a commercial product of such polyamide epoxy resin, “Smiles Resin 650” and “Smiles Resin 675” sold by Sumika Chemtex Co., Ltd., “WS-525” sold by Japan PMC Co., Ltd. and so on. When mix | blending a water-soluble epoxy resin, the addition amount is about 1-100 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resin, Preferably it is 1-50 weight part.

  After injecting the aqueous adhesive thus obtained between the optically anisotropic layer and the substrate, water is evaporated by drying and the thermal crosslinking reaction is allowed to proceed, thereby providing sufficient adhesion to both. be able to.

  The active energy ray-curable adhesive is not particularly limited as long as it is cured by irradiation with active energy rays and can bond the layer including the optically anisotropic layer and the substrate with a strength sufficient for practical use. For example, a cationic polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator, a radical polymerizable active energy ray-curable adhesive containing an acrylic curing component and a radical polymerization initiator, An active energy ray curable adhesive containing both a cationic polymerizable curing component such as an epoxy compound and a radical polymerizable curing component such as an acrylic compound, in which a cationic polymerization initiator and a radical polymerization initiator are blended. Examples thereof include an electron beam curable adhesive that is cured by irradiating an electron beam to an active energy ray curable adhesive that does not contain an agent and an initiator. Among these, a cationic polymerizable active energy ray-curable adhesive containing an epoxy compound and a cationic polymerization initiator is preferable. Further, it is more preferable that the adhesive can be used substantially without a solvent.

  A cationically polymerizable epoxy compound that is liquid at room temperature, has proper fluidity even in the absence of a solvent, and gives an appropriate cured adhesive strength, and a suitable cation The active energy ray-curable adhesive containing the polymerization initiator can omit the drying equipment that is usually required. In addition, by irradiating with an appropriate active energy dose, the curing rate can be accelerated and the production rate can be improved.

  The active energy ray-curable adhesive can contain a sensitizer as necessary. By using a sensitizer, the reactivity is improved, and the mechanical strength and adhesive strength of the adhesive layer can be further improved. As the sensitizer, those described above can be appropriately applied.

  When mix | blending a sensitizer, it is preferable that the compounding quantity shall be the range of 0.1-20 weight part with respect to 100 weight part of total amounts of an active energy ray hardening-type adhesive agent.

  Various additives can be blended with the active energy ray-curable adhesive within a range that does not impair the effect. Examples of additives that can be blended include ion trapping agents, antioxidants, chain transfer agents, tackifiers, thermoplastic resins, fillers, flow regulators, plasticizers, and antifoaming agents.

  The active energy ray-curable adhesive can be applied to the film by the application method described above. In this case, the viscosity of the active energy ray-curable adhesive may be any as long as it has a viscosity that can be applied by various methods, but the viscosity at a temperature of 25 ° C. is in the range of 10 to 30,000 mPa · sec. It is preferable that it is in the range of 50 to 6,000 mPa · sec. If the viscosity is too small, it tends to be difficult to obtain a uniform coating without unevenness. On the other hand, when the viscosity is too large, it tends to be difficult to flow, and it is difficult to obtain a uniform coating film with no unevenness. The viscosity here is a value measured at 60 rpm after adjusting the temperature of the adhesive to 25 ° C. using a B-type viscometer.

  The active energy ray curable adhesive can be used in an electron beam curable type or an ultraviolet curable type. Examples of the active energy ray include the same as those described above and an active electron beam.

  In the electron beam curable type, any appropriate condition can be adopted as the electron beam irradiation condition as long as the active energy ray curable adhesive can be cured. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV.

  Electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under a condition in which a small amount of oxygen is introduced.

In the ultraviolet curable type, the light irradiation intensity of the active energy ray curable adhesive is determined for each composition of the adhesive and is not particularly limited, but is preferably 10 to 5000 mW / cm ² . When the light irradiation intensity to the resin composition is less than 10 mW / cm ² , the reaction time becomes too long, and when it exceeds 5000 mW / cm ² , adhesion occurs due to heat radiated from the light source and heat generated during polymerization of the composition. It may cause yellowing or deterioration of the constituent material of the agent. The irradiation intensity is preferably an intensity in a wavelength region effective for activation of the photocationic polymerization initiator, more preferably an intensity in a wavelength region of a wavelength of 400 nm or less, and further preferably a wavelength region of a wavelength of 280 to 320 nm. Strength. Such once with light intensity or by irradiation a plurality of times, the integrated light quantity 10 mJ / cm ² or more, preferably be set to be 10~5,000mJ / cm ^2. When the integrated light quantity to the adhesive is less than 10 mJ / cm ² , the generation of active species derived from the polymerization initiator is not sufficient, and the curing of the adhesive becomes insufficient. On the other hand, when the integrated light quantity exceeds 5,000 mJ / cm ² , the irradiation time becomes very long, which is disadvantageous for improving productivity. At this time, depending on the film to be used, the combination of adhesive types, and the like, it is different in which wavelength region (UVA (320 to 390 nm), UVB (280 to 320 nm), etc.) the accumulated light amount is necessary.

  Examples of the light source used for polymerizing and curing the adhesive by irradiation with active energy rays are the same as those described above. From the viewpoint of energy stability and simplicity of the apparatus, an ultraviolet light source having a light emission distribution at a wavelength of 400 nm or less is preferable.

Hereinafter, the present invention will be described in more detail with reference to examples. Unless otherwise specified, “%” and “parts” in the examples are% by mass and part by mass.
ZF-14 manufactured by Nippon Zeon Co., Ltd. was used for the cycloolefin polymer film (COP).
AGF-B10 manufactured by Kasuga Electric Co., Ltd. was used for the corona treatment device.
The corona treatment was performed once using the above corona treatment device under the conditions of an output of 0.3 kW and a treatment speed of 3 m / min.
SPOT CURE SP-7 with a polarizer unit manufactured by USHIO INC. Was used as the polarized UV irradiation device.
Olympus Corporation LEXT was used for the laser microscope.
UNICURE VB-15201BY-A manufactured by USHIO INC. Was used as the high pressure mercury lamp.
The phase difference value was measured using KOBRA-WR manufactured by Oji Scientific Instruments.

溶剤（９５部）：シクロペンタノン
Example 1
[Preparation of composition for forming photo-alignment film]
The following components were mixed, and the resulting mixture was stirred at 80 ° C. for 1 hour to obtain a photoalignment film-forming composition (1-1). The following photo-alignment materials were synthesized by the method described in JP2013-33248A.
Photo-alignment material (5 parts):

Solvent (95 parts): Cyclopentanone

[Preparation of Composition (1)]
The following components were mixed, and the resulting mixture was stirred at 80 ° C. for 1 hour to obtain a composition (1).

The polymerizable liquid crystal A1 and the polymerizable liquid crystal A2 were synthesized by the method described in JP 2010-31223 A.
Polymerizable liquid crystal A1 (12.31 parts):

Polymerizable liquid crystal A2 (0.86 parts):

Polymerization initiator (0.73 parts):
2-Dimethylamino-2-benzyl-1- (4-morpholinophenyl) butan-1-one (Irgacure 369; manufactured by Ciba Specialty Chemicals)
Leveling agent (0.01 parts): polyacrylate compound (BYK-361N; manufactured by BYK-Chemie)
Solvent: cyclopentanone (52.2 parts) N-methyl-2-pyrrolidone (NMP) (34.8 parts)

Example (1-1)
A polyethylene terephthalate film (PET) (Diafoil T140E25 manufactured by Mitsubishi Plastics, Inc.) is output using a corona processing device (AGF-B10, manufactured by Kasuga Denki Co., Ltd.) under conditions of an output of 0.3 kW and a processing speed of 3 m / min. Processed once. A photo-alignment film-forming composition (1-1) is applied to the corona-treated surface with a bar coater, dried at 80 ° C. for 1 minute, and a polarized UV irradiation device (SPOT CURE SP-7; manufactured by USHIO INC.) ) Was used to carry out polarized UV exposure with an integrated light quantity of 100 mJ / cm ² . It was 122 nm when the film thickness of the obtained alignment film was measured with the ellipsometer (Ellipsometer M-220, JASCO Corporation make). Subsequently, the composition (1) was applied onto the alignment film using a bar coater, dried at 120 ° C. for 1 minute, and then used with a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by USHIO INC.). Then, ultraviolet rays are irradiated from the surface side on which the composition (1) is applied (from the direction B) (in a nitrogen atmosphere, wavelength: 365 nm, integrated light amount at wavelength 365 nm: 1000 mJ / cm ² ), and further from the PET substrate side ( An optical film including an optically anisotropic layer was formed by irradiating ultraviolet rays (from a direction A) under a nitrogen atmosphere (wavelength: 365 nm, integrated light quantity at wavelength 365 nm: 500 mJ / cm ² ). After the adhesive was bonded to the obtained optical film, it was processed once using a corona treatment device (AGF-B10, manufactured by Kasuga Denki Co., Ltd.) under conditions of an output of 0.3 kW and a treatment speed of 3 m / min. It was bonded to a cycloolefin polymer film (COP) (ZF-14, manufactured by Nippon Zeon Co., Ltd.). Then, the optical film which transferred the optically anisotropic layer to the COP film was obtained by peeling the PET film as the base material. At this time, the transferred layer was only the optically anisotropic layer, and the alignment film was present on the base PET film. Since the film was uniformly peeled between the alignment film and the optically anisotropic layer, the transfer was easy. When the retardation values of the obtained optical film at a wavelength of 450 nm and a wavelength of 650 nm were measured, the retardation value was 120 to 150 nm, and the relationship between the in-plane retardation values at each wavelength was as follows.
Re (450) / Re (550) = 0.85
Re (650) / Re (550) = 1.03
That is, the optically anisotropic layer had optical characteristics represented by the following formulas (3), (4) and (6-2). Note that since the phase difference value of the COP at the wavelength of 550 nm is substantially 0, the relationship between the in-plane phase difference values is not affected.
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
100 nm <Re (550) <160 nm (6-2)

Example (1-2)
The same operation as in Example (1-1) was performed except that the integrated light quantity at a wavelength of 365 nm in the second ultraviolet irradiation was changed to 1000 mJ / cm ² . When the optically anisotropic layer was transferred, the transfer was easy because the film was uniformly peeled between the alignment film and the optically anisotropic layer.

Example (1-3)
The same operation as in Example (1-1) was performed except that the integrated light quantity at a wavelength of 365 nm in the second ultraviolet irradiation was changed to 3000 mJ / cm ² . When the optically anisotropic layer was transferred, the transfer was easy because the film was uniformly peeled between the alignment film and the optically anisotropic layer.

Comparative Example (1-1)
The same operation as in Example (1-1) was performed except that the integrated light amount at a wavelength of 365 nm in the second ultraviolet irradiation was changed to 0 mJ / cm ² , that is, the second ultraviolet irradiation was not performed. When the optically anisotropic layer was transferred, the transfer was easy because the film was uniformly peeled between the alignment film and the optically anisotropic layer.

Comparative Example (1-2)
During the first ultraviolet irradiation, exposure was performed through a UV cut filter (UTVAF-50S-34U, manufactured by Sigma Kouki Co., Ltd.), and the other operations were the same as in Example (1-1). When transferring the optically anisotropic layer, the film could not be uniformly peeled between the alignment film and the optically anisotropic layer.

Comparative Example (1-3)
The same operation as Comparative Example (1-1) was performed except that the integrated light quantity at a wavelength of 365 nm in the first ultraviolet irradiation was changed to 1500 mJ / cm ² . When the optically anisotropic layer was transferred, the transfer was easy because the film was uniformly peeled between the alignment film and the optically anisotropic layer.

Comparative Example (1-4)
The same operation as in Example (1-1) was performed except that the integrated light amount at a wavelength of 365 nm in the first ultraviolet irradiation was changed to 500 mJ / cm ² . When transferring the optically anisotropic layer, the film could not be uniformly peeled between the alignment film and the optically anisotropic layer.

  The optical films shown in Examples (1-1) to (1-3) and Comparative Examples (1-1) to (1-4) obtained were bonded to glass via an adhesive, and 85 Table 1 shows the results of measuring the amount of decrease in the retardation value after standing at 120 ° C. for 120 hours.

  According to the production method of the present invention, the transfer of the layer including the optically anisotropic layer formed on the alignment film of the substrate having the alignment film is facilitated, and further the optically anisotropic layer under high temperature drying conditions. The decrease in the in-plane retardation value can be suppressed.

1, 1 'roll 1A, 1A' winding core 2, 2 'roll 2A, 2A' winding core 3, 3 'cooling device 4, 4' ultraviolet irradiation device

Claims (12)

Including a step of applying a composition containing a polymerizable liquid crystal compound on an alignment film of a laminate having a base material and an alignment film, and a step of irradiating active energy rays to the laminate on which the composition has been applied. A method for producing an optical film comprising:
The step of irradiating the active energy ray includes two or more active energy ray irradiations, and includes an active energy ray energy in the first active energy ray irradiation and an active energy ray energy in the second active energy ray irradiation. The manufacturing method of the optical film whose ratio satisfy | fills following formula (2-1) and the energy of the active energy ray in the second active energy ray irradiation is 10-10000 mJ / cm < ² >.
15> (first irradiation energy) / (second irradiation energy)> 0.1 (2-1) The step of irradiating the active energy ray is performed according to claim 1, wherein the ratio of the intensity of the wavelength 380 nm to the wavelength 365 nm of the active energy ray spectrum satisfies the following formula (1) in at least one active energy ray irradiation. Manufacturing method of optical film.
Intensity of light having a wavelength of 380 nm / Intensity of light having a wavelength of 365 nm> 0.1 (1)   The method for producing an optical film according to claim 1 or 2, wherein the step of irradiating active energy rays includes irradiation of active energy rays from the side of the surface on which the polymerizable liquid crystal compound is applied.   The manufacturing method of the optical film of Claim 3 which irradiates an active energy ray from the base material side before, after or before and after irradiation of the active energy ray from the surface side in which the polymerizable liquid crystal compound is applied.   The manufacturing method of the optical film of Claim 3 which irradiates an active energy ray from the polymeric liquid crystal compound side after the active energy ray irradiation from the surface side in which the polymeric liquid crystal compound is apply | coated. The ratio of the energy of the active energy ray in the first active energy ray irradiation and the energy of the active energy ray in the second active energy ray irradiation satisfies the following formula (2-2): The manufacturing method of the optical film of description.
10> (first irradiation energy) / (second irradiation energy)> 0.2 (2-2) The method for producing an optical film according to claim 1, wherein the optically anisotropic layer is an optically anisotropic layer satisfying the following formulas (3) and (4).
Re (450) / Re (550) ≦ 1.00 (3)
1.00 ≦ Re (650) / Re (550) (4)
(In the formula, Re (λ) represents an in-plane retardation value for light having a wavelength of λ nm.) The method for producing an optical film according to claim 1, wherein the optically anisotropic layer is an optically anisotropic layer satisfying the following formula (6-2).
100 nm <Re (550) <160 nm (6-2)
(In the formula, Re (550) represents an in-plane retardation value for light having a wavelength of 550 nm.)   The method for producing an optical film according to claim 1, wherein the optical anisotropic layer has a thickness of 0.3 to 5 μm.   The method for producing an optical film according to claim 1, wherein the composition containing a polymerizable liquid crystal compound is a composition containing a polymerizable liquid crystal compound and a polymerization initiator.   The method for producing an optical film according to claim 1, wherein the alignment film is a photo-alignment film.   The method for producing an optical film according to claim 1, wherein the alignment film has a thickness of 10 to 1000 nm.

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